智慧型無線感應器系統平臺建構與其在土木結構診斷應用之研究---子計畫：利用無線監測系統於土木工程之微動及破壞試驗量測與分析(I)

Abstract

無線監測系統為目前監測系統之發展主流之一。無線監測系統優於傳統有線監測系 統，最明顯者為佈置省時，而且監測系統每一頻道（channel）之單價較低。針對土木工 程之監測所需而發展特定無線監測系統是本整合案之主要目標。 本子計畫為兩年計畫，其主要目的有二：（1）應用或測試本整合案所發展之無線監 測系統；（2）利用時變系統觀念建立結構系統損害指標。第一年將利用所發展之無線監 測系統於橋樑之微動量測；並與傳統微動量測系統比較所量測之速度均方根值（rms， 以三分之一八分倍頻表示）；並進一步利用小波轉換技巧識別所量測橋樑之模態特性。 另外，亦將發展一程序利用移動最小平方差法配合多項式基底建立TVARX（Time Varying AutoRegressive with eXogenous inputs）模式，並進而估算結構系統之瞬時模態參 數。第二年則將應用所發展無線監測系統於振動台試驗；借用國家地震工程研究中心之 大型振動台進行RC 梁柱接頭或鋼構梁柱接頭破壞試驗。由於實驗將進行至梁柱接頭破 壞；若使用傳統有線監測系統，則其纜線可能防礙實驗之進行。然後，再利用第一年所 發展之識別技巧建立實驗數據之TVARX 模式，進而發展損害指標。

Wireless monitoring becomes an attracting research theme in recent years as a promising technology that could greatly impact the field of structural monitoring and infrastructure asset management. A wireless monitoring system is usually superior to a traditional monitoring system that has cables connecting its sensors and data acquisition system when the cost and labor on setting up a monitoring system are concerned. The main purpose of the whole project consisting of several subprojects is to develop a wireless monitoring system specializing in applications of civil engineering. This subproject is a two year project, which has two main purposes: (1) verifying the capability of the developed wireless monitoring system through field testing; (2) developing a damage index for a structural system by considering the structure as a time varying system in the process of damage. In the first year, the developed wireless monitoring system will be applied to measure ambient vibrations of a highway bridge. The measured responses will compare with those obtained from a traditional monitoring system. The comparison will be carried out in terms of the root mean squares of measured velocity responses and the identified modal parameters of the bridge. The modal parameters will be identified via a wavelet transform based technique developed by the writer recently. In addition to it, a new approach on establishing TVARX （Time Varying AutoRegressive with eXogenous inputs） for a time varying linear system will be also proposed as pre-required work for the second year. The new approach uses polynomial basis along with a moving least squares technique to establish so called shape functions for the time varying coefficients in TVARX. The instantaneous modal parameters of the time varying structural system will be estimated from the established TVARX. In the second year, the developed wireless monitoring system will be used on measuring the responses of a beam-column connection under shaking table tests, which will be carried out in NCREE. The beam-column connection will be shaken to collapse. If a traditional measuring system is used, its cables may influence the performance of the test. The measured responses will be processed via the approach developed in the first year to establish an appropriate TVARX. Then, a damage index may be found from the identified instantaneous modal parameters.